Eric Holder, 29, of Los Angeles, is being sought by police.
Holder, a suspected gang member who knew Hussle, allegedly approached the rapper and two other men several times at the star's Marathon Clothing store in the Hyde Park neighborhood of Los Angeles before engaging in a conversation with Hussle, Police Chief Michel Moore said at a news conference on Tuesday, declining to say what the conversation was about.
Holder then left the store, returned with a gun, walked up to Hussle and the two other men as they stood in the parking lot of the store and fired numerous shots, investigators said.
He fled in a waiting vehicle driven by an unidentified female. Hussle died from gunshot wounds to his head and torso, the Los Angeles County Medical Examiner-Coroner said Monday.
Investigators do not believe the killing was gang related, according to Moore, who said Holder and Hussle had a personal dispute.
Let our news meet your inbox. The news and stories that matters, delivered weekday mornings.
Moore said his department is working with the district attorney's office to obtain an arrest warrant for Holder and warned that anyone helping Holder hide from police could face charges.
"There should be no safe haven for this individual," he said. Officers also wish to speak with the female driver.
Los Angeles Mayor Eric Garcetti recalled working with Hussle on how to get more African Americans involved in the technology industry and called the rapper "gifted and brilliant."
"Nipsey Hussle was an artist that touched our city," he said. "He was a tireless advocate for the young people of this city and the world … and his impact on our city was deep.”
Fire officials said 19 people were transported to hospitals from Monday's vigil. Two were in critical condition, including one who had been struck by a vehicle. Two other people were in serious condition. Law enforcement officials told NBC News that at least one person was stabbed.
Fire officials said the majority of those hospitalized appeared to have suffered "trample injuries" as people fell or were knocked to the ground as panicked crowds fled the scene.
LAFD is treating several of the injured on the corner of Crenshaw and Slauson. LAPD says reports of a shooting appaer to be inaccurate #NBCLApic.twitter.com/1S6uw2phho
Authorities said they had found no evidence of gunshot wounds.
Police Chief Moore said in an interview on KNX radio that a disturbance, possibly a fight, broke out about 8:30 p.m. local time at the vigil, which set off "a cascading series of events that caused a lot of turmoil."
Los Angeles Police Detective Meghan Aguilar described the scene at the vigil as “absolutely chaotic."
“People scattered in all directions" amid the "mass panic," Aguilar told KNBC.
She said one person had been detained for disorderly conduct.